nub vs haecceity

nub and haecceity both are nouns.

Word	Noun	Adjective	Verb	Adverb
nub	Yes	No	No	No
haecceity	Yes	No	No	No

As nouns, haecceity is a hyponym of nub; that is, haecceity is a word with a more specific, narrower meaning than nub:

nub: the choicest or most essential or most vital part of some idea or experience
haecceity: the essence that makes something the kind of thing it is and makes it different from any other

Other hyponyms of nub include bare bones, hypostasis, quiddity, quintessence, stuff.

nub (noun)	haecceity (noun)
the choicest or most essential or most vital part of some idea or experience	the essence that makes something the kind of thing it is and makes it different from any other
a small piece
a small lump or protuberance